Gram-scale Preparation of Acyl Fluorides and Their Reactions with Hindered Nucleophiles

A series of acyl fluorides was synthesized at 100 mmol scale using phase transfer catalyzed halogen exchange between acyl chlorides and aqueous bifluoride solution. The convenient procedure consists of vigorous stirring of the biphasic mixture at rt, followed by extraction and distillation. Isolated acyl fluorides (usually 7 g to 20 g) display excellent purity, and can be transformed into sterically hindered amides and esters, when treated with lithium amide bases and alkoxides under mild conditions.

Ultrafast SET-LRP in biphasic mixtures of the non-disproportionating solvent acetonitrile with water

The two kinetic regime, low conversion and low chain end functionality seen in copper catalyzed polymerization of acrylates in acetonitrile was transformed into a SET-LRP kinetic, to complete conversion and quantitative chain end functionality in a biphasic mixture containing 10% water.

A boundary-integral representation for biphasic mixture theory, with application to the post-capillary glycocalyx

We describe a new boundary-integral representation for biphasic mixture theory, which allows us to efficiently solve certain elastohydrodynamic–mobility problems using boundary element methods. We apply this formulation to model the motion of a rigid particle through a microtube which has non-uniform wall shape, is filled with a viscous Newtonian fluid, and is lined with a thin poroelastic layer. This is relevant to scenarios such as the transport of small rigid cells (such as neutrophils) through microvessels that are lined with an endothelial glycocalyx layer (EGL). In this context, we examine the impact of geometry upon some recently reported phenomena, including the creation of viscous eddies, fluid flux into the EGL, as well as the role of the EGL in transmitting mechanical signals to the underlying endothelial cells.

Effect of Substituents on the Electrochemical Reversible Discharge Capacity of Cobalt Hydroxide Electrodes

Cobalt hydroxide, nickel hydroxide-cobalt hydroxide and zinc oxide-cobalt hydroxide biphasic mixtures were prepared by precipitation method. In spite of structural similarities exhibited by nickel hydroxide and cobalt hydroxide samples, former is a good electrode material and exchanges 1e-/Ni while latter does not show any reversibility. Presence of small amount of other metal ions such as nickel or zinc in the lattice of cobalt hydroxide or as a biphasic mixture of cobalt hydroxide-nickel hydroxide/cobalt hydroxide- zinc oxide, exchange up to 0.2 to 0.24e- exchange compared to pure cobalt hydroxide which shows 0.1 e- exchange.

Thermal Decomposition Studies of Layered Metal Hydroxynitrates (Metal: Cu, Zn, Cu/Co, and Zn/Co)

Layered metal hydroxynitrates and mixed metal hydroxynitrates (copper/cobalt hydroxynitrates and zinc/cobalt hydroxynitrates at different mole ratios) were synthesized by hydrolysis of urea and metal nitrates at 140°C. Layered metal hydroxyl nitrates derive their structure from brucite mineral and generally crystallize in hexagonal and monoclinic phases. Isothermal decomposition studies of Cu2(OH)3(NO3), Co2(OH)3(NO3), Cu1.5Co0.5(OH)3(NO3), Cu1.34Co0.66(OH)3(NO3), Zn5(OH)8(NO3)2(H2O)2, Zn3.75Co1.25(OH)8(NO3)2(H2O)2, and Zn3.35Co1.65(OH)8(NO3)2(H2O)2 samples were carried out at different intervals of temperature and the structural transformations during the process were monitored using powder X-ray diffractograms. Biphasic mixture of metal hydroxynitrate/metal oxide is observed in case of cobalt/zinc based layered hydroxynitrates, while copper hydroxynitrate or copper/cobalt metal hydroxynitrate decomposes in a single step. The decomposition temperatures of layered metal hydroxynitrates and mixed layered metal hydroxides depend on the method of preparation, their composition and the nature of metal ion, and their coordination.